diff --git a/1到6问（这里main函数是第6问，看其他问需要稍改动main函数）.c b/1到6问（这里main函数是第6问，看其他问需要稍改动main函数）.c
new file mode 100644
index 0000000..7ad9a5c
--- /dev/null
+++ b/1到6问（这里main函数是第6问，看其他问需要稍改动main函数）.c
@@ -0,0 +1,239 @@
+#include<stdio.h>
+#include<string.h>
+struct student
+{
+        char num[10];
+        float Math;
+        float Physic;
+        float English;
+        float sum;
+        float ave;
+        int class;
+        int inserted;//sign whether the student is inserted
+        char name[10];
+        int mod;//sign whether the student is modified
+};
+void menu()// print menu
+{
+        for(int i=0;i<30;i++)
+        printf(" ");
+        printf("1.Input\n");
+        for(int i=0;i<30;i++)
+        printf(" ");
+        printf("2.Output\n");
+        for(int i=0;i<30;i++)
+        printf(" ");
+        printf("3.Order\n");
+        for(int i=0;i<30;i++)
+        printf(" ");
+        printf("4.Quit\n");
+}
+void OSmenu(char x)// operation on menu
+{
+        if(x=='i')
+        printf("You are trying to Input info\n");
+        else if(x=='o')
+        printf("You are trying to Output info\n");
+        else if(x=='m')
+        printf("You are trying to Make things ordered\n");
+        else if(x=='q')
+        printf("You are about to Quit\n");
+        else
+        printf("Wrong input\n");
+}
+void inputstudent(struct student *t)//input info without class
+{
+        scanf("%s %f %f %f",&(t->num),&(t->Math),&(t->Physic),&(t->English));
+        t->sum=t->Math+t->Physic+t->English;
+        t->ave=t->sum/3;
+        t->inserted=0;
+        t->mod=0;
+}
+void inputstudent2(struct student *t)//input info with class
+{
+        scanf("%s %d %f %f %f",&(t->num),&(t->class),&(t->Math),&(t->Physic),&(t->English));
+        t->sum=t->Math+t->Physic+t->English;
+        t->ave=t->sum/3;
+        t->inserted=0;
+        t->mod=0;
+}
+void inputstudent3(struct student *t)//input info with class name
+{
+        scanf("%s %d %s %f %f %f",&(t->num),&(t->class),&(t->name),&(t->Math),&(t->Physic),&(t->English));
+        t->sum=t->Math+t->Physic+t->English;
+        t->ave=t->sum/3;
+        t->inserted=0;
+        t->mod=0;
+}
+void insertstudent(struct student *t)//insert student
+{
+        scanf("%s %d %f %f %f",&(t->num),&(t->class),&(t->Math),&(t->Physic),&(t->English));
+        t->sum=t->Math+t->Physic+t->English;
+        t->ave=t->sum/3;
+        t->inserted=1;
+}
+void outputstudent1(struct student *t)// output num and grade of all subject
+{
+        printf("%s %.1f %.1f %.1f %.1f\n",t->num,t->Math,t->Physic,t->English,t->sum);
+}
+void outputstudent2(struct student *t)// output num,sum and ave
+{
+        printf("%s %.1f %.1f\n",t->num,t->sum,t->ave);
+}
+void outputstudent3(struct student *t)// output num,class,whether inserted and grade of all subject
+{
+        if(t->inserted==0)
+        printf("%s %d %.1f %.1f %.1f\n",t->num,t->class,t->Math,t->Physic,t->English);
+        else
+        printf("%s %d %.1f %.1f %.1f inserted\n",t->num,t->class,t->Math,t->Physic,t->English);
+}
+void outputstudent4(struct student *t)// output num,class,name,and grade of all subject
+{
+        printf("%s %s %d %.1f %.1f %.1f\n",t->num,t->name,t->class,t->Math,t->Physic,t->English);
+}
+void outputstudent5(struct student*t)//output info by class
+{
+        for(int i=0;i<3;i++)
+        {
+                if(i==0||(t+i)->class!=(t+i-1)->class)
+                {
+                        if((t+i)->mod==1)
+                        printf("%d %s %s %.1f %.1f %.1f modified\n",(t+i)->class,(t+i)->num,(t+i)->name,(t+i)->Math,(t+i)->Physic,(t+i)->English);
+                        else
+                        printf("%d %s %s %.1f %.1f %.1f\n",(t+i)->class,(t+i)->num,(t+i)->name,(t+i)->Math,(t+i)->Physic,(t+i)->English);
+                }
+                else
+                {
+                        if((t+i)->mod==1)
+                        printf("   %s %s %.1f %.1f %.1f modified\n",(t+i)->num,(t+i)->name,(t+i)->Math,(t+i)->Physic,(t+i)->English);
+                        else
+                        printf("   %s %s %.1f %.1f %.1f\n",(t+i)->num,(t+i)->name,(t+i)->Math,(t+i)->Physic,(t+i)->English);
+                }
+        }
+}
+void orderstudent(struct student *t,int n)//order without class
+{
+        for(int i=0;i<n;i++)
+        {
+                for(int j=i;j<n;j++)
+                {
+                        if((t+i)->sum>(t+j)->sum)
+                        {
+                                struct student m;
+                                m=*(t+i);
+                                *(t+i)=*(t+j);
+                                *(t+j)=m;
+                        }
+                }
+        }
+}
+void orderstudent2(struct student *t,int n)//order with class
+{
+        for(int i=0;i<n;i++)
+        {
+                for(int j=i;j<n;j++)
+                {
+                        if((t+i)->class>(t+j)->class)
+                        {
+                                struct student m;
+                                m=*(t+i);
+                                *(t+i)=*(t+j);
+                                *(t+j)=m;
+                        }
+                }
+        }
+        for(int i=0;i<n;i++)
+        {
+                for(int j=i;j<n;j++)
+                {
+                        if((t+i)->class==(t+j)->class&&(t+i)->sum<(t+j)->sum)
+                        {
+                                struct student m;
+                                m=*(t+i);
+                                *(t+i)=*(t+j);
+                                *(t+j)=m;
+                        }
+                }
+        }
+}
+void removestudent(struct student *t)//remove student(num or name)
+{
+        for(int i=0;i<3;i++)
+        outputstudent4(t+i);
+        char re[10];
+        char p;
+        scanf("%s",re);
+        for(int i=0;i<3;i++)
+        {
+                if(strcmp((t+i)->num,re)!=0&&strcmp((t+i)->name,re)!=0)
+                {
+                        outputstudent4(t+i);
+                }
+        }
+        printf("Are you sure(yes/no)?\n");
+        scanf("%c",&p);
+        scanf("%c",&p);
+        if(p=='n')
+        {
+                for(int i=0;i<3;i++)
+            outputstudent4(t+i);
+        }
+        else
+        {
+                for(int i=0;i<3;i++)
+                {
+                        if(strcmp((t+i)->num,re)==0||strcmp((t+i)->name,re)==0)
+                        {
+                                for(int j=i;j<2;j++)
+                                {
+                                        *(t+j)=*(t+j+1);
+                                }
+                        }
+                }
+        }
+}
+void modstudent(struct student *t)//mod info according to num
+{
+        struct student f;
+        inputstudent3(&f);
+        for(int i=0;i<3;i++)
+        {
+                if(strcmp((t+i)->num,f.num)==0)
+                {
+                        *(t+i)=f;
+                        (t+i)->mod=1;
+                }
+        }
+}
+int main()
+{
+        struct student s[10];
+        strcpy(s[0].num,"10001");
+        strcpy(s[0].name,"Zhang");
+        s[0].class=11;
+        s[0].Math=99.5;
+        s[0].Physic=88.5;
+        s[0].English=89.5;
+        s[0].sum=s[0].Math+s[0].Physic+s[0].English;
+        s[0].inserted=0;
+        strcpy(s[1].num,"10002");
+        strcpy(s[1].name,"Yang");
+        s[1].class=12;
+        s[1].Math=77.9;
+        s[1].Physic=56.5;
+        s[1].English=87.5;
+        s[1].sum=s[1].Math+s[1].Physic+s[1].English;
+        s[1].inserted=0;
+        strcpy(s[2].num,"10003");
+        strcpy(s[2].name,"Liang");
+        s[2].class=11;
+        s[2].Math=92.5;
+        s[2].Physic=99.0;
+        s[2].English=60.5;
+        s[2].sum=s[2].Math+s[2].Physic+s[2].English;
+        s[2].inserted=0;
+        orderstudent2(&s[0],3);
+        modstudent(&s[0]);
+        outputstudent5(&s[0]);
+        return 0;
+}
\ No newline at end of file